Photographic developer



Patented Feb. 11, .1936

PHOTOGRAPHIC DEVELOPER Heinrich Ulrich and Karl Saurwein, Ludwigs.hafen-on-the-Rhein,

Germany, assignors to Agfa Ansco Corporation, Binghamton, N. Y., a

corporation of New York No Drawing. Application December 22, 1933,

Serial No. 1932 7 Claims.

This invention relates to a photographic developer and more particularlyto such a developer in which the usual alkali or the usual preservativeor both have been replaced by compounds hitherto not known for thispurpose.

One of its objects is to provide a developer in which the usual alkaliand the preservative are replaced by a compound uniting both functions.A further object is to replace the usual alkali compo ds by compounds ofwhich the alkalinity can be adjusted in a degree not hitherto known.

For certain purposes of photographic development it is desirable to haveonly a weakly alkaline developer in order to avoid drawbacks involvedwith the use of stronger alkaline developers.

According to this invention it has been found that the salts ofhydroxyalkylamines with weak acids are excellently suited to replace formany purposes the alkali hitherto used in developers. The use of thesalt of a weak acid of a hydroxyalkylamine involves the advantage thatthe alkalinity of the developer can be adjusted to any requirement. Ashydroxyalkylamines which are suitable, there is mentioned, for instance,mono-, dior triethanolamine, propanolamine, butanolamine,oleylethanolamine, furthermore cyclohexylethanolamine,hydroxyethylmorpholine, hydroxyethylpiperidine,hydroxyethylethylenediamine, ethyldiethanolamine or the like, furtherthe ethers or hydroxyethers obtainable from hydroxyalkylamines byetherification with alcohols or by reaction with ethylene oxide or thelike. The substitution products of the amines enumerated likewise may beused. All ammonia derivatives. are suitable which contain in theirmolecule one or several alkyl radicals with one or several hydroxygroups, and, if required, contain still further aliphatic,cycloaliphatic or mononuclear aromatic radicals. Suitable weak acidsare, for instance, carbonic acid and sulfurous acid. The salts ofhydroxya'lkylamines with sulfurous acid present furthermore theadvantage that they are capable to replace the preservative of the usualdevelopers. Therefore, it is possible to produce photographic developerswhich contain besides the developing agent the sulfite of anhydroxyalkylamine which replaces both, the usual alkali and thepreservative.

The salts of the hydroxyalkylamines with the weak acids are easilyobtainable by reacting with the compounds on each other. If the acid isgaseous, for instance, in the case of sulfurous acid, thehydroxyalkylamine is saturated with the gas it the amine is liquid.

703,672. In Germany December 24,

The compounds enumerated above may, for instance, be added to thedeveloping baths customary in the photographic industry, for instance,solutions of aminophenols, hydroquinone, hydroxyphenylglycine and thelike. They may also be applied in combination with other substancessuitable for the development of photographic plates, films and the like,for instance with sodium bisulfite, acetone bisulfite and the like. I

The-following examples serve. to illustrate the invention:

Example 1 Monomethylparaminophenol sulfate" I 2 grams Triethanolamine 5cc. Triethanolamine sulfite 3 (:0. Water to 100 cc.

For use this solution is diluted by parts of water on one part ofconcentrated developer.

Example 2 Monomethylparaminophenol sulfate- 3 grams Triethanolaminesulfite 6 cc. Potassium bromide 0,2 gram Water to 500 cc.

Example 3 Water; 500 cc. Monomethylparaminophenol sulfate- 1,5 gramTriethanolamine 8 cc. Butanolamine sulfite 10 cc. Potassium bromide 1gram Example 4 Water 500 cc. Monomethylparaminophenol sulfate- 0,3 gramHydroquinone 0,4 gram Sodium carbonate sicc 4gramsEthanolcyclohexylamine sulfite 5 grams Potassium bromide 2 grams Ourinvention is not limited to the foregoing examples. Other weak acidsalts of other hydroxyalkylamines maybe used and we contemplate asincluded within our invention all such modifications and equivalents asfall within the scope of the appended claims.

The term hydroxyalkylamine in the specification and the claims isintended to include amines containing at least one alkylhydroxy radicallinked to the nitrogen atom of the amine.

What we claim is:

1. A photographic developer. comprising a developing agent and a weakacid salt of a hydroxyalkylamine.

2. A photographic developer comprising a developing agent and a weakacid salt of a hydroxyalkylamine selected from the group consisting ofcarbonates and sulfites.

3. A photographic developer comprising a developing agent and thesulflte of a hydroxyalkylamine.

4. A photographic developer comprising a developing' agent and a weakacid salt of a hydroxyalkyi-amine selected from the group consisting ofmonoethanol-amine, diethanol-amine, triethanol-amine, propanol-amine,butanolamine, oleylethanol-amine, cyclohexylethanolamine,hydroxyethyl-morpholine, hydroxyethylpiperidine,hydroxyethylethylene-diamine, and ethyldiethanol-amine.

5. A developer comprising monomethylparaaminophenol sulfate,triethanolamine, triethanolamine sulfite and water.

6. A developer comprising monomethylparaaminophenol sulfate, triethanolamine sulfite, potassium bromide and water.

'7. A developer comprising monomethylparaaminophenol sulfate,hydroquinone, sodium carbonate sicc., ethanol cyclohexylamine sulflte,potassium bromide and water.

HEINRICH ULRICH. KARL SAURWEIN.

